Forbes Billionaires 2013: The Top 20

1. Carlos Slim Helu & Family $73 Bln Telecom, Mexico Age: 73Slim is the world’s richest person for the fourth year in a row, up $4 billion from our 2012 list. Pan-Latin American mobile telecom outfit América Móvil remains his most valuable holding, at $36 billion; the company spread its wings to Europe in the past year, buying pieces of Dutch telecom firm KPN and Telekom Austria. Slim also bought a stake in a struggling Spanish soccer team in November.

2. Bill Gates $67 Bln Microsoft, United States Age: 57Bill Gates, the world’s most generous philanthropist, has already given more than $28 billion and has been spreading his gospel to other billionaires near and far: He and Warren Buffett added 12 non-Americans to their Giving Pledge in February, bumping the total to 105 high net worth individuals. As chairman, Gates still owns about 5 percent of Microsoft but admitted that the company’s early mobile phone strategy was “a mistake”.

3. Amancio Ortega $57 Bln Zara, Spain Age: 76Ortega is the year’s biggest gainer, up $19.5 billion. He stepped down as chairman of Inditex, best known for Zara, in 2011, but still owns nearly 60 percent of its shares, which soared 50 percent year-over-year on record profits. Ortega also has a real estate portfolio estimated to be worth more than $4 billion. The son of a railway worker, he started out as a golfer in a shirt store.

4. Warren Buffett $53.5 Bln Berkshire Hathaway, United States Age: 82Buffett slips out of the top three for the first time since 2000, despite gaining $9.5 billion. In February, Berkshire announced a deal with Brazilian billionaire Jorge Paulo Lemann’s 3G Capital to snap up iconic ketchup producer HJ Heinz Company for $23 billion. Completed radiation treatment for prostate cancer in 2012.

5. Larry Ellison $43 BlnOracle, United States Age: 68Software titan’s fortune rose $7 bill-ion along with Oracle’s shares. Ellison is investing tech earnings in property, spending a reported $500 million for the Hawaiian island of Lanai in 2012. His daughter Megan’s film Zero Dark Thirty was nominated for an Academy Award. Ellison has donated at least $445 million to his foundation to support research on ageing and age-related diseases.

6. Charles Koch $34 Bln Diversified United States Age: 776. David Koch $34 Bln Diversified United States Age: 72The world’s richest brothers failed to unseat Barack Obama as President in 2012, as the conservative firebrands had planned, but Koch Industries forges ahead with $115 billion in estimated sales and rising earnings from refining, building materials and consumer products. Fun fact: Their Georgia Pacific group apparently sells approximately $1 billion in toilet paper a year. Charles is CEO in Wichita, while David—the richest New Yorker—runs the chemical technology side.